- test and fix receiving text/html attachment in multipart/mixed situations

They are now preserved as attachment, instead of diving into parsing-html
  and simplifying.

- adapt mime-debugging

src/dc_receive_imf.rs

@@ -47,12 +47,10 @@ pub fn dc_receive_imf(
         server_uid,
     );
 
-    /*
-    if std::env::var(crate::DCC_MIME_DEBUG).is_ok() {
+    if std::env::var(crate::DCC_MIME_DEBUG).unwrap_or_default() == "2" {
         info!(context, "dc_receive_imf: incoming message mime-body:");
         println!("{}", String::from_utf8_lossy(imf_raw));
     }
-    */
 
     let mime_parser = MimeParser::from_bytes(context, imf_raw);
     let mut mime_parser = if let Err(err) = mime_parser {

src/e2ee.rs

@@ -247,13 +247,13 @@ fn decrypt_if_autocrypt_message<'a>(
     // Errors are returned for failures related to decryption of AC-messages.
 
     let encrypted_data_part = match wrapmime::get_autocrypt_mime(mail) {
-        Err(err) => {
-            // not a proper autocrypt message, abort and ignore
-            info!(context, "Not an autocrypt message: {:?}", err);
+        Err(_) => {
+            // not an autocrypt mime message, abort and ignore
             return Ok(None);
         }
         Ok(res) => res,
     };
+    info!(context, "Detected Autocrypt-mime message");
 
     decrypt_part(
         context,

src/mimeparser.rs

@@ -2,7 +2,7 @@ use std::collections::{HashMap, HashSet};
 
 use deltachat_derive::{FromSql, ToSql};
 use lettre_email::mime::{self, Mime};
-use mailparse::MailHeaderMap;
+use mailparse::{DispositionType, MailHeaderMap};
 
 use crate::aheader::Aheader;
 use crate::blob::BlobObject;
@@ -22,6 +22,7 @@ use crate::param::*;
 use crate::peerstate::Peerstate;
 use crate::securejoin::handle_degrade_event;
 use crate::stock::StockMessage;
+use crate::{bail, ensure};
 
 #[derive(Debug)]
 pub struct MimeParser<'a> {
@@ -110,7 +111,7 @@ impl<'a> MimeParser<'a> {
                     mail_raw = raw;
                     let decrypted_mail = mailparse::parse_mail(&mail_raw)?;
                     if std::env::var(crate::DCC_MIME_DEBUG).is_ok() {
-                        info!(context, "dc_receive_imf: incoming message mime-body:");
+                        info!(context, "decrypted message mime-body:");
                         println!("{}", String::from_utf8_lossy(&mail_raw));
                     }
 
@@ -509,100 +510,63 @@ impl<'a> MimeParser<'a> {
         let (mime_type, msg_type) = get_mime_type(mail)?;
         let raw_mime = mail.ctype.mimetype.to_lowercase();
 
+        let filename = get_attachment_filename(mail);
         info!(
             self.context,
-            "add_single_part_if_known {:?} {:?}", mime_type, msg_type
+            "add_single_part_if_known {:?} {:?} {:?}", mime_type, msg_type, filename
         );
 
         let old_part_count = self.parts.len();
 
-        let is_attachment = mail
-            .get_content_disposition()?
-            .params
-            .iter()
-            .any(|(key, _value)| key.starts_with("filename"));
-
-        // regard `Content-Transfer-Encoding:`
-        match mime_type.type_() {
-            mime::TEXT | mime::HTML if !is_attachment => {
-                let decoded_data = match mail.get_body() {
-                    Ok(decoded_data) => decoded_data,
-                    Err(err) => {
-                        warn!(self.context, "Invalid body parsed {:?}", err);
-                        // Note that it's not always an error - might be no data
-                        return Ok(false);
-                    }
-                };
-
-                // check header directly as is_send_by_messenger is not yet set up
-                let is_msgrmsg = self.lookup_field("Chat-Version").is_some();
-
-                let mut simplifier = Simplify::new();
-                let simplified_txt = if decoded_data.is_empty() {
-                    "".into()
-                } else {
-                    let is_html = mime_type == mime::TEXT_HTML;
-                    simplifier.simplify(&decoded_data, is_html, is_msgrmsg)
-                };
-
-                if !simplified_txt.is_empty() {
-                    let mut part = Part::default();
-                    part.typ = Viewtype::Text;
-                    part.mimetype = Some(mime_type);
-                    part.msg = simplified_txt;
-                    part.msg_raw = Some(decoded_data);
-                    self.do_add_single_part(part);
+        if let Ok(filename) = filename {
+            self.do_add_single_file_part(
+                msg_type,
+                mime_type,
+                &raw_mime,
+                &mail.get_body_raw()?,
+                &filename,
+            );
+        } else {
+            match mime_type.type_() {
+                mime::IMAGE | mime::AUDIO | mime::VIDEO | mime::APPLICATION => {
+                    bail!("missing attachment");
                 }
+                mime::TEXT | mime::HTML => {
+                    let decoded_data = match mail.get_body() {
+                        Ok(decoded_data) => decoded_data,
+                        Err(err) => {
+                            warn!(self.context, "Invalid body parsed {:?}", err);
+                            // Note that it's not always an error - might be no data
+                            return Ok(false);
+                        }
+                    };
 
-                if simplifier.is_forwarded {
-                    self.is_forwarded = true;
-                }
-            }
-            mime::TEXT
-            | mime::HTML
-            | mime::IMAGE
-            | mime::AUDIO
-            | mime::VIDEO
-            | mime::APPLICATION => {
-                // try to get file name from
-                //    `Content-Disposition: ... filename*=...`
-                // or `Content-Disposition: ... filename*0*=... filename*1*=... filename*2*=...`
-                // or `Content-Disposition: ... filename=...`
+                    // check header directly as is_send_by_messenger is not yet set up
+                    let is_msgrmsg = self.lookup_field("Chat-Version").is_some();
 
-                let ct = mail.get_content_disposition()?;
-                let mut desired_filename = ct
-                    .params
-                    .iter()
-                    .filter(|(key, _value)| key.starts_with("filename"))
-                    .fold(String::new(), |mut acc, (_key, value)| {
-                        acc += value;
-                        acc
-                    });
-
-                if desired_filename.is_empty() {
-                    if let Some(param) = ct.params.get("name") {
-                        // might be a wrongly encoded filename
-                        desired_filename = param.to_string();
-                    }
-                }
-
-                // if there is still no filename, guess one
-                if desired_filename.is_empty() {
-                    if let Some(subtype) = mail.ctype.mimetype.split('/').nth(1) {
-                        desired_filename = format!("file.{}", subtype,);
+                    let mut simplifier = Simplify::new();
+                    let simplified_txt = if decoded_data.is_empty() {
+                        "".into()
                     } else {
-                        return Ok(false);
+                        let is_html = mime_type == mime::TEXT_HTML;
+                        simplifier.simplify(&decoded_data, is_html, is_msgrmsg)
+                    };
+
+                    if !simplified_txt.is_empty() {
+                        let mut part = Part::default();
+                        part.typ = Viewtype::Text;
+                        part.mimetype = Some(mime_type);
+                        part.msg = simplified_txt;
+                        part.msg_raw = Some(decoded_data);
+                        self.do_add_single_part(part);
+                    }
+
+                    if simplifier.is_forwarded {
+                        self.is_forwarded = true;
                     }
                 }
-                self.do_add_single_file_part(
-                    msg_type,
-                    mime_type,
-                    &raw_mime,
-                    &mail.get_body_raw()?,
-                    &desired_filename,
-                );
+                _ => {}
             }
-            _ => {}
         }
 
         // add object? (we do not add all objects, eg. signatures etc. are ignored)
@@ -651,6 +615,7 @@ impl<'a> MimeParser<'a> {
                 return;
             }
         };
+        info!(self.context, "added blobfile: {:?}", blob.as_name());
 
         /* create and register Mime part referencing the new Blob object */
         let mut part = Part::default();
@@ -902,12 +867,13 @@ pub struct Part {
     pub param: Params,
 }
 
+/// return mimetype and viewtype for a parsed mail
 fn get_mime_type(mail: &mailparse::ParsedMail<'_>) -> Result<(Mime, Viewtype)> {
     let mimetype = mail.ctype.mimetype.parse::<Mime>()?;
 
     let viewtype = match mimetype.type_() {
         mime::TEXT => {
-            if !mailmime_is_attachment_disposition(mail) {
+            if !is_attachment_disposition(mail) {
                 match mimetype.subtype() {
                     mime::PLAIN | mime::HTML => Viewtype::Text,
                     _ => Viewtype::File,
@@ -941,14 +907,62 @@ fn get_mime_type(mail: &mailparse::ParsedMail<'_>) -> Result<(Mime, Viewtype)> {
     Ok((mimetype, viewtype))
 }
 
-fn mailmime_is_attachment_disposition(mail: &mailparse::ParsedMail<'_>) -> bool {
-    if let Some(ct) = mail.ctype.params.get("Content-Disposition") {
-        return ct.to_lowercase().starts_with("attachment");
+fn is_attachment_disposition(mail: &mailparse::ParsedMail<'_>) -> bool {
+    if let Ok(ct) = mail.get_content_disposition() {
+        return ct.disposition == DispositionType::Attachment
+            && ct
+                .params
+                .iter()
+                .any(|(key, _value)| key.starts_with("filename"));
     }
 
     false
 }
 
+fn get_attachment_filename(mail: &mailparse::ParsedMail) -> Result<String> {
+    // try to get file name from
+    //    `Content-Disposition: ... filename*=...`
+    // or `Content-Disposition: ... filename*0*=... filename*1*=... filename*2*=...`
+    // or `Content-Disposition: ... filename=...`
+
+    let ct = mail.get_content_disposition()?;
+    ensure!(
+        ct.disposition == DispositionType::Attachment,
+        "disposition not an attachment: {:?}",
+        ct.disposition
+    );
+
+    let mut desired_filename = ct
+        .params
+        .iter()
+        .filter(|(key, _value)| key.starts_with("filename"))
+        .fold(String::new(), |mut acc, (_key, value)| {
+            acc += value;
+            acc
+        });
+    println!("get_attachment_filename1: {:?}", desired_filename);
+
+    if desired_filename.is_empty() {
+        if let Some(param) = ct.params.get("name") {
+            // might be a wrongly encoded filename
+            desired_filename = param.to_string();
+        }
+    }
+    println!("get_attachment_filename2: {:?}", desired_filename);
+
+    // if there is still no filename, guess one
+    if desired_filename.is_empty() {
+        if let Some(subtype) = mail.ctype.mimetype.split('/').nth(1) {
+            desired_filename = format!("file.{}", subtype,);
+        } else {
+            bail!("could not determine filename: {:?}", ct.disposition);
+        }
+    }
+    println!("get_attachment_filename3: {:?}", desired_filename);
+
+    Ok(desired_filename)
+}
+
 // returned addresses are normalized.
 fn get_recipients<S: AsRef<str>, T: Iterator<Item = (S, S)>>(headers: T) -> HashSet<String> {
     let mut recipients: HashSet<String> = Default::default();
@@ -1053,6 +1067,29 @@ mod tests {
         assert_eq!(recipients.len(), 2);
     }
 
+    #[test]
+    fn test_is_attachment() {
+        let raw = include_bytes!("../test-data/message/mail_with_cc.txt");
+        let mail = mailparse::parse_mail(raw).unwrap();
+        assert!(!is_attachment_disposition(&mail));
+
+        let raw = include_bytes!("../test-data/message/mail_attach_txt.eml");
+        let mail = mailparse::parse_mail(raw).unwrap();
+        assert!(!is_attachment_disposition(&mail));
+        assert!(!is_attachment_disposition(&mail.subparts[0]));
+        assert!(is_attachment_disposition(&mail.subparts[1]));
+    }
+
+    #[test]
+    fn test_get_attachment_filename() {
+        let raw = include_bytes!("../test-data/message/html_attach.eml");
+        let mail = mailparse::parse_mail(raw).unwrap();
+        assert!(get_attachment_filename(&mail).is_err());
+        assert!(get_attachment_filename(&mail.subparts[0]).is_err());
+        let filename = get_attachment_filename(&mail.subparts[1]).unwrap();
+        assert_eq!(filename, "test.html")
+    }
+
     #[test]
     fn test_mailparse_content_type() {
         let ctype =

test-data/message/html_attach.eml

@@ -0,0 +1,25 @@
+Chat-Disposition-Notification-To: tmp_6272287793210918@testrun.org
+Subject: =?utf-8?q?Chat=3A_File_=E2=80=93_test=2Ehtml?=
+Message-ID: Mr.XA6y3og8-az.WGbH9_dNcQx@testrun.org
+Date: Sat, 07 Dec 2019 19:00:27 +0000
+X-Mailer: Delta Chat Core 1.0.0-beta.12/DcFFI
+Chat-Version: 1.0
+To: <tmp_5890965001269692@testrun.org>
+From: "=?utf-8?q??=" <tmp_6272287793210918@testrun.org>
+Content-Type: multipart/mixed; boundary="mwkNRwaJw1M5n2xcr2ODfAqvTjcj9Z"
+
+
+--mwkNRwaJw1M5n2xcr2ODfAqvTjcj9Z
+Content-Type: text/plain; charset=utf-8
+
+-- 
+Sent with my Delta Chat Messenger: https://delta.chat
+
+--mwkNRwaJw1M5n2xcr2ODfAqvTjcj9Z
+Content-Type: text/html
+Content-Disposition: attachment; filename="test.html"
+Content-Transfer-Encoding: base64
+
+PGh0bWw+PGJvZHk+dGV4dDwvYm9keT5kYXRh
+
+--mwkNRwaJw1M5n2xcr2ODfAqvTjcj9Z--

test-data/message/mail_attach_txt.eml

@@ -0,0 +1,40 @@
+From holger@merlinux.eu Sat Dec  7 11:53:58 2019
+Return-Path: <holger@merlinux.eu>
+X-Original-To: holger+test@merlinux.eu
+Delivered-To: holger+test@merlinux.eu
+Received: from [127.0.0.1] (localhost [127.0.0.1])
+	(using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits))
+	(No client certificate requested)
+	by mail.merlinux.eu (Postfix) with ESMTPSA id 61825100531;
+	Sat,  7 Dec 2019 10:53:58 +0000 (UTC)
+DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=merlinux.eu;
+	s=default; t=1575716038;
+	bh=xhaPssQzVOHRafcciTQqDnZ1Zi4GMwsmg9pHLH3i8P8=;
+	h=Date:From:To:Subject;
+	b=U4HxGDZ8RwLwRPFtIvRsb+x5BiyICnbbY2ZOGlZdLt12MuDTfiYi/phHiQUC402EY
+	 GXb8dYgYr5+0PDiPBa7dyt2VQLC/h9QRfOA82tb1vpJYC+KksSAH0nYQqJvs7XrqCN
+	 i95/jwZnsWrV7w72+xsrO5qPujIE68TmM5I9Cyec=
+Received: by beto.merlinux.eu (Postfix, from userid 1000)
+	id 229D3820070; Sat,  7 Dec 2019 11:53:58 +0100 (CET)
+Date: Sat, 7 Dec 2019 11:53:57 +0100
+From: holger krekel <holger@merlinux.eu>
+To: holger+test@merlinux.eu
+Subject: hello
+Message-ID: <20191207105357.GA6266@beto>
+MIME-Version: 1.0
+Content-Type: multipart/mixed; boundary="YiEDa0DAkWCtVeE4"
+Content-Disposition: inline
+
+--YiEDa0DAkWCtVeE4
+Content-Type: text/plain; charset=us-ascii
+Content-Disposition: inline
+
+siehe anhang
+
+--YiEDa0DAkWCtVeE4
+Content-Type: text/plain; charset=us-ascii
+Content-Disposition: attachment; filename="x.txt"
+
+hello
+
+--YiEDa0DAkWCtVeE4--